Process for the preparation of metallic beryllium by electrolysis



Patented ay 19, 193

EROCESS FOR THE T E BER Gustav llaegengltle rr'rrou or am nu annornornzsrs n-lisenburg in H,

No Drawing. Application .iully 0, 1934., Serial No.

ZMAM. Him

Germany Juli? re. 1033 4 i. (@i. km)

The object of my invention is a process for the preparation of pure beryllium metal by electrolysls.

It has been known before to prepare beryllium metal from beryllium chloride by electrolysis in which electrolysis a mixture of beryllium chloride and sodium chloride is utilized as electrolyte. This electrolysis has always been carried out with a great excess of sodium chloride. In consequence of the high melting point of the sodium chloride the temperature of the electrolyte had to be kept at a range of about 730 to 820 C. All the prescriptions therefore give an average temperature of 800 which corresponds approximately may have a melting to the fusion point of sodium chloride. Since beryllium chloride, however, fuses already at 405 C.as is well known-its vapor tension at a bath temperature of 800 is a very high one. Therefore very considerable quantities vaporize already which either get lost or have to be recovered in a rather complicated device.

According to my invention I carry out the electrolysis of the beryllium chloride by using a mixture of beryllium chloride and alkali metal chloride the fusion point of which is below 450 centigrade, and effecting the electrolysis at temperatures of 450 centigrade and lower.

Mixtures of beryllium chlorlde'and alkali metal Y chloride which melt below 450 centigrade contain, as has been ascertained, a minimum of 30 percent beryllium chloride. The contents of the bath mixture as regards beryllium chloride may be raised considerably. The upper limit for in- ..creasing the contents as regards beryllium chloride in the electrolyte is given by the fact that pure beryllium chloride itself is a very bad conductor of the electric current or none at all. For

this reason one is compelled to add to theberyllium chloride. certain quantities of conducting salts. As such. I use alkali metal chlorides. With great advantage I have used for the electrolysis mixtures which contain about 40 to percent beryllium chloride whilst the rest consists of alkali metal chloride for instance sodium chloride or potassium chloride. Such mixtures point as low as 360 C. In some cases a mixture or both these salts may be used. when using a mixture consisting of about 50 parts of beryllium chloride and 50 parts of sodium chloride the most-favorable temperature for carrying out the electrolysis was found to be 370 to 380 centigrade.

The process according to my invention ofiers advantage in various directions. the electrolysis is carried out at a comparatively low temperature-which in itself is already a great advantage-causes the loss of beryllium chloride by vaporization to be reduced to a minimum. Furthermore, at this temperature the melt is completely indifferent towards thematerial forming the vessel of the electric bath, and its viscosity is a very low one. The process of my invention works with excellent current yields which amount to as high as nearly percent.-

The beryllium metal which is obtained by working according to my invention is deposited in solid flakes which are exceedingly pure so that they may be fused to a regulus without any difiiculty for instance in a current of hydrogen or nitrogen. Losses are practically avoided when working-in accordance with my invention which on the other hand always occur when the metal is deposited in a pulverulent or gritty condition.

What I claim is:

l. A process for the preparation of beryllium metal by electrolysis from a mixture of beryllium chloride and alkali metal chloride which comprises using as electrolyte a mixture containing 50 parts of sodium chloride and 50 parts of beryllium chloride and electrolyzing at a bath temperature of between 3'70 to 380 centigrade.

2. A process for the preparation of beryllium metal which consists in electrolyzing at a temperature ofbetween 350 C. and 450 C. a fused mixture oi beryllium chloride and alkali metal chloride containing at least 30% of beryllium chloride.

3., A process for the preparation of beryllium metal which consists in electrolyzing at a temperature of between 370 C. and 380 C. a fused mixture or beryllium chloride and alkali metal chloride containing at least 30% of beryllium chloride.

4. A process for the preparation of beryllium metal which consists in electrolyzing at a temperature below 450' C. a fused mixture of beryl-- lium chloride and alkali metal chloride containing from 40% to 60% of beryllium chloride.

ous'rav mess.

The fact that 

